Question

probe that sin^2 18+cos^2 36=3/4

Answer 1

sin^2 18+cos^2 36
={(√5-1)/4}^2+{(√5+1)/4}^2
={(√5-1)^2+(√5+1)^2}/16
=2{(√5)^2+1}/16
={2×(5+1)}/16
=12/16
=3/4

{According to trigonometric ratios of submultiple angles sin18= {(√5-1)/4} and cos36={(√5+1)/4}.

Answer 2

Answer:

Step-by-step explanation: